I personally think that if you can find the Gen4 TRD muffler to get those. I have em on my 99 and the sound is amazing. Its not enough to be droning and painful for extended driving but it is plenty loud when you feed it some throttle. Light footed city driving with the windows down yields pleasing sound while the windows up its barely audible in the winter. People always yank their heads around to see what car is revving up when I dump the pedals
I got the laugh of my life when I "spooked" a corvette owner. I was too busy gasping for breath from laughter to try and explain to him he had absolutley no reason to be afraid of my slow arse camry.
make it look and sound smexy as hell. Don't worry about HP. Unless you dump many 10's of thousands like Tony and a few other guys you will never have to worry about HP.
M.H.O.
Enjoy the car